package com.test.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

@Controller
public class UploadController {
    // @RequestParam("file") 将name=file控件得到的文件封装成CommonsMutipartFile对象
    @RequestMapping("/upload")
    public String upload(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request, Model model) throws IOException {
        //获取文件名称
        String uploadFileName = file.getOriginalFilename();
        //如果文件为空，直接返回
        if("".equals(uploadFileName)){
            return "redirect:/index.jsp";
        }
        System.out.println("上传文件名称："+uploadFileName);
        //上传路径保存设置
        String path = request.getServletContext().getRealPath("/upload");
        //如果路径不存在，创建
        File realPath = new File(path);
        if(!realPath.exists()){
            realPath.mkdir();
        }
        System.out.println("上传文件保存地址："+realPath);
        InputStream is = file.getInputStream(); //文件输入流
        OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //文件输出流
        //读取写出
        int len = 0;
        byte[] buffer = new byte[1024];
        while((len=is.read(buffer)) != -1){
            os.write(buffer,0,len);
            os.flush();
        }
        os.close();
        is.close();
        model.addAttribute("fileName",uploadFileName);
        return "redirect:/index.jsp";
    }

    @RequestMapping("/upload2")
    public String upload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
        //上传路径保存设置
        String path = request.getServletContext().getRealPath("/upload");
        File realPath = new File(path);
        if(!realPath.exists()){
            realPath.mkdir();
        }
        //上传文件地址
        System.out.println("上传文件保存地址："+realPath);
        //通过CommonsMutipartFile的方法直接写文件
        file.transferTo(new File(realPath+"/"+file.getOriginalFilename()));

        return "redirect:/index.jsp";
    }
    // 下载图片
    @RequestMapping("download")
    public String downloads(HttpServletResponse response,HttpServletRequest request) throws IOException {
        //要下载的图片地址
        String path = request.getServletContext().getRealPath("/upload");
        String fileName = "基础语法.jpg";

        // 1. 设置response 相应头
        response.reset(); //设置页面不缓存，清空buffer
        response.setCharacterEncoding("UTF-8"); //字符编码
        response.setContentType("multipart/form-data"); //二进制传输数据
        //设置相应头
        response.setHeader("Content-Disposition","attachment;fileName"+ URLEncoder.encode(fileName,"UTF-8"));

        File file = new File(path,fileName);
        //2读取文件--输入流
        InputStream input = new FileInputStream(file);
        //3. 写出文件 -- 输出流
        OutputStream out = response.getOutputStream();

        //读取写出
        int len = 0;
        byte[] buffer = new byte[1024];
        while((len=input.read(buffer)) != -1){
            out.write(buffer,0,len);
            out.flush();
        }
        out.close();
        input.close();
        return "ok";
    }
}
